dswancutt,
Really comes down to personal preference, I like OWB holsters and seem to gravitate towards the kydex type holsters. The one I have for my M&P 9fs is a Blade Tech with a drop and offset, I recently picked up a Shield and found a holster company called Tuaga and they make a leather holster with a kydex paddle and this is so comfortable that I may have to buy one for my M&P .40c. Lots of guys like IWB but I trided a KIng Tuck by Galco and it was a pain in two areas, I didn't care for the stuggle to get it on and when I put the gun in it it rode right on my Hip bone and annoyed me because I had a hip replacement done so I returned it. I think you just have to keep trying different holsters until you find one thats does what you want it to do.